It may not be often that you give your mouse a lot of thought, but I just had one of those moments where I thought “Wow! What a great mouse.”
I use a Logitech VX when I’m portable and a Logitech MX at my desktop. These are basically the same mouse with some small differences that make each better for the environment they were designed to be used in. The key feature on both is a scroll wheel that is able to work (as many scroll wheels do) in a mode that sort of clicks as you scroll, and a mode that is unique where it is free to spin like the Price-is-right Big Wheel. This last mode is by far my favorite. When you are on a long document of any sort it is really nice to be able to give the wheel a little flick and have the page scroll along until you stop the wheel. The wheel is weighted to keep it moving and has a good-enough build quality that it doesn’t feel like a cheap feature as one might expect that it would.